Remove the outer damaged leaves from the leeks. Trim away the base and cut away the green tops leaving about
When cold arrange in a serving dish and prepare the dressing. Place a seasoning of salt and freshly milled pepper into a mixing basin. Add the sugar, vinegar and mustard. Stir to blend then add the oil and mix well. Taste the dressing for sharpness – add a little more vinegar if required. Add the chopped parsley or chervil and spoon over the leeks. Marinate until ready to serve. Then garnish with the sliced hard-boiled eggs.